322.png

Specifically, in the 1968 July–December records, (indexed as page 322) covers renewal registrations for authors and titles such as:

: Renewals for The Mystery at the Moss-Covered Mansion (Nancy Drew series). Other Potential Matches 322.png

While the Project Gutenberg file is the most likely "paper" or document reference, "322.png" also appears in other contexts: in the 1968 July–December records